Patients diagnosed with unresectable locally advanced Triple Negative Breast Cancer (TNBC) usually have poor outcome for its aggressive clinical behaviour. Atezolizumab plus nanoparticle albumin-bound (nab)-Paclitaxel prolonged progression-free survival (PFS) and overall survival (OS) among patients with unresectable locally advanced TNBC but its use is hampered by the lack of reliable predictors of tumor response. Seventy-seven consecutive patients with unresectable locally advanced TNBC treated with Atezolizumab plus nab-Paclitaxel were studied by blood draws at baseline, 28 days and 56 days after initiation of treatment. Exosomal PD-L1 mRNA in plasma was determined using Bio-Rad QX100 digital droplet PCR system and exoRNeasy kit and objective responses were defined following the RECIST criteria v.1.1. The study evaluates whether PD-L1 mRNA copies per ml in plasma-derived exosomes may predict response to anti-PD-L1 antibodies early in the course of therapy. Our data showed patients with unresectable locally advanced TNBC and higher levels of PD-L1 mRNA expression in plasma-derived exosomes at baseline demonstrated greater response to atezolizumab plus nab-paclitaxel. Furthermore, the levels of mRNA decreased with successful treatment while the copy number increased in patients experiencing disease progression following atezolizumab plus nab-paclitaxel. For the first time, our data showed the usefulness of assessment of exosomal PD-L1 as non-invasive real-time biopsy in patients diagnosed with TNBC suggesting exosomal PD-L1 is significantly associated with outcome and response to Atezolizumab plus nab-Paclitaxel.

The biological heterogeneity of glioblastoma (GBM), the most aggressive type of brain cancer, is a critical hallmark, caused by changes in the genomic mutational asset and influencing the clinical progression over the time. The understanding and monitoring of the mutational profile is important not only to reveal novel therapeutic targets in this set of patients, but also to ameliorate the clinical stratification of subjects and the prognostic significance. As neurosurgery represents the primary technique to manage GBM, it is of outmost importance to optimize alternative and less invasive methods to monitor the dynamic mutation profile of these patients. Extracellular vesicles (EV) are included in the liquid biopsy analysis and have emerged as the biological mirror of escaping and surviving mechanisms by many tumors as well as glioblastoma. Very few studies have investigated the technical feasibility to detect and analyze the genomic profile by Next Generation Sequencing (NGS) in circulating EV of patients with grade IV glioblastoma. Here, we attempted to characterize and to compare with the corresponding matched tissue samples, potential variants with pathogenic significance of the DNA contained in peripheral blood derived EV. The NGS analysis has revealed that patients with grade IV glioblastoma, exhibited lesser DNA content in EV than controls and that both in EV and matched cancer tissues, the NF1 gene was consistently mutated in all patients with the c.2568C>G as the most common pathogenic variant expressed. This study supports the clinical utility of the circulating EV in glioblastoma and as eligible tool for personalized medicine.